10 测试设备................................................................................................................................166 10.1 简介....................................................................................................................166 10.2 电缆....................................................................................................................167 10.2.1 电缆衰减......................................................................................................168 10.2.2 电缆耦合......................................................................................................169 10.2.3 电缆屏蔽......................................................................................................170 10.2.4 传输阻抗......................................................................................................170 10.2.5 使用铁氧体磁珠改善电缆性能 .............................................................174 10.2.5.1 阻抗 .............................................................................................174 10.2.6 设备互连（不匹配）....................................................................................176 10.3 信号发生器.............................................................................................................177 10.4 衰减器.............................................................................................................178 10.4.1 测试中使用的衰减器场地验证程序................................................178 10.4.2 衰减器